Shoulder ROM orthosis

Abstract

Therapeutic abduction of the shoulder joint is achieved using a hinged device, the hinge activated by a cable passed between pulleys to increase mechanical advantage. The cable is wound on a spool mounted on a ratcheting mechanism, whereby tension is maintained as the spool is wound via a knob or computer controlled motor. A rotation control device enables rotation of the spool by a user, but prevents rotation due to a load. Mating shackles pivot in connection with the hinge, and are activated by the cable to increase the angle of the hinge. The hinge is connected to the body, one portion affixed relative to the body, the other affixed relative to the upper arm. As the hinge angle is expanded, the shoulder joint is abducted, stretching the tissue of the joint. If resilient, the cable imparts a dynamic tensioning force to the shoulder joint. Medial or lateral rotation is accomplished by a second device disposed at the elbow, wherein the pivot point of internal/external rotation is along the axis of the upper arm.

What is claimed is: 
     
       1. A device for stretching tissue of a joint in a body of a patient, said device comprising:
 a force application assembly comprising:
 a first hinge including
 a first hinge portion affixable to a first portion of the patient's body on a first side of the joint; 
 a second hinge portion pivotally connected to said first hinge portion, affixable to a second portion of the patient's body on a second side of the joint; and 
 a spool; 
 
 a second hinge connected to said first hinge, operative to increase an angle of the first hinge thereby changing an angle of the joint to stretch tissue of the joint, when an angle of the second hinge is increased; 
 a first pulley; 
 a second pulley formed between said first hinge and said second hinge; 
 a resilient cable operatively engaged with said spool, said first pulley, and said second pulley, wherein said spool is configured to apply a tension to said cable whereby tension on said cable applies a force to said first and second hinges in a direction of increasing an angle of said first and second hinges; 
 wherein when said free end of said cable is affixed relative to said second pulley, said resilience of said cable is operative to impart a continuous force to said first and second hinges in a direction of increasing an angle of said first and second hinges; and 
 a drive assembly coupled to the force application assembly, said drive assembly configured to move the second body portion with respect to the first body portion, wherein said drive assembly is further configured to maintain said spool in a position of applying tension to said cable; wherein said drive assembly further comprises:
 a first circular raceway; 
 at least one rotatable element; 
 a second raceway disposed in concentrically rotating conformity with said first circular raceway, having at least one curved surface operative to support said rotatable element between said first and second raceways, whereby when said first circular raceway is rotated in a first direction, said curved surface urges said rotatable element to a position in binding conformity between said first and second raceways, preventing rotation of said first raceway with respect to said second raceway; and 
 a plurality of pins configured to prevent said rotatable element from moving to said position in binding conformity when said second raceway is rotated. 
 
 
 
     
     
       2. The device of  claim 1 , further comprising:
 a gear, connected to said second hinge portion; 
 a curved rack, driven by said gear; 
 a frame, connected to said rack, operative to support a third portion of the patient's body; and 
 a shaft configured to turn said gear; 
 whereby when said gear is turned, said third portion of the patient's body is moved relative to said second portion of the patient's body. 
 
     
     
       3. The device of  claim 1 , wherein said first hinge further comprises pivot connection including a slot and a hole, said pivot connection configured to apply a distractive force to the joint, wherein said slot includes an increasing radius. 
     
     
       4. The device of  claim 1 , wherein said pivotal connection between said first hinge portion and said second hinge portion further comprises:
 two pins; 
 two apertures formed through an area of one of said first and second hinge portions; and 
 first and second elongated slots formed through an area of the other of said first and second hinge portions, the first slot defining a longitudinal axis having a direction corresponding to a distraction of the joint, and the second slot defining a curved shape corresponding to a movement of the joint resulting in a distraction of the joint; 
 whereby one each of said two pins pass through said first and second slots, respectively, connecting said first and second hinge portions, whereby said first and second hinge portions are constrained relative to each other to define an arc of movement corresponding to a distraction of the joint as an angle of said second hinge is increased. 
 
     
     
       5. The device of  claim 1 , wherein said drive assembly further comprises a ratchet and a pawl. 
     
     
       6. The device of  claim 1 , wherein said rotation control subassembly comprises a projection associated with said second raceway operative to block movement of said rotatable element to said position in binding conformity. 
     
     
       7. The device of  claim 1 , wherein said drive assembly further comprises a clutch configured to prevent rotation of said spool in a direction to release a tension of said cable. 
     
     
       8. A device for stretching tissue of a joint in a body of a patient, comprising:
 a first hinge including
 a first hinge portion affixable to a first portion of the patient's body on a first side of the joint; and 
 a second hinge portion pivotally connected to said first hinge portion, affixable to a second portion of the patient's body on a second side of the joint; 
 
 a spool associated with said first hinge portion; 
 a first pulley associated with said second hinge portion; 
 a cable extending between said spool and said first pulley; 
 a drive shaft configured to apply a rotational force to said first pulley whereby a tension is applied to said cable and said first hinge portion is urged to move relative to said second hinge portion; 
 a drive assembly configured to limit a rotation of said first pulley, said drive assembly including
 a first circular raceway; 
 at least one rotatable element; and 
 a second raceway disposed in concentrically rotating conformity with said first circular raceway, having at least one curved surface operative to support said rotatable element between said first and second raceways, whereby when said first circular raceway is rotated in a first direction, said curved surface urges said rotatable element to a position in binding conformity between said first and second raceways, preventing rotation of said first raceway with respect to said second raceway; and 
 
 a plurality of pins configured to prevent said rotatable element from moving to said position in binding conformity when said second raceway is rotated. 
 
     
     
       9. The device of  claim 8 , wherein said second raceway comprises a projection operative to block movement of said rotatable element to said position in binding conformity. 
     
     
       10. The device of  claim 8 , further including:
 a second pulley associated with said first and second hinge portions; 
 whereby said cable passes through said first and second pulleys. 
 
     
     
       11. The device of  claim 8 , wherein said drive assembly is configured to limit a rotation in both directions of rotation of said first pulley. 
     
     
       12. The device of  claim 8 , wherein said cable is resilient. 
     
     
       13. A device for stretching tissue of a joint in a body of a patient, comprising:
 a first hinge including
 a first hinge portion affixable to a first portion of the patient's body on a first side of the joint; and 
 a second hinge portion pivotally connected to said first hinge portion, affixable to a second portion of the patient's body on a second side of the joint; 
 
 a second hinge connected between said first and second hinge portions; 
 a cable extending between one of said first and second hinge portions and said second hinge; 
 a spool, connected to said cable, operative to apply a tension to said cable to increase an angle of said second hinge, thereby increasing an angle of said first hinge to cause stretching of joint tissue; 
 a drive assembly configured to limit a rotation of said spool, including 
 a first circular raceway connected to said spool; 
 at least one rotatable element; and 
 a second raceway disposed in concentrically rotating conformity with said first circular raceway, having at least one curved surface operative to support said rotatable element between said first and second raceways, whereby when said first circular raceway is rotated in a first direction, said curved surface urges said rotatable element to a position in binding conformity between said first and second raceways, preventing rotation of said first raceway with respect to said second raceway; and 
 a plurality of pins configured to prevent said rotatable element from moving to said position in binding conformity when said second raceway is rotated. 
 
     
     
       14. The device of  claim 13 , wherein said cable is resilient, and wherein said resilience of said cable is operative to impart a continuous force to said first and second hinges in a direction of increasing an angle of said first and second hinges.